Cutting a hole in SS sink.

[Doggus]

What's the best way to do it? I'm putting in a Costco RO system. I've seen where some in newsgroups recommend doing it with a Greenlee punch but the drawback is it leaves the surrounding metal a little 'wavy' from the stress of the punch.

I saw a Culligan guy do it with a drill of some sort on my parents sink many years ago. I think I'll do that but not sure what kind of hole saw or if I need to use something else.

Thank yee!

Hmmmm, this may get me contradicted but here's what I would try if I had it to do: I have an abrasive 1 1/4 inch holesaw that I bought at a ceramic tile supply for boring holes in the tile for faucet stems. Cost me $18, I think. There should also be smaller sizes available. You will need to change out the pilot bit because it comes with a masonry bit in it. I think that would allow you to cut SS without snagging in the thin material. But I would also use some rubber-footed woodworker's clamps to secure a hardwood block under the spot, then carefully drill your pilot hole, beginning with a small bit (1/8th" or so) & work up to the required 1/4" pilot. It might even be worth clamping a block on both sides, but use oak or a hardwood equivalent. This helps protect the adjacent surface from warping or tearing. If you use two blocks, ditch the rubber-foot clamps & go to all steel. And of course, pre-bore the top block with a regular holesaw as the abrasive will just clog & smoke on wood. Be aware that an abrasive bit will likely be a little bit inexact in actual diameter. You might want to do a test hole on some sheet metal scrap; I probably would.

[one_rod]

Cutter is quite right.
Carbide Grit holesaws will go through stainless more reliably than anything else. We used to use these a lot on catering equipment.
Stainless steel can be pretty unpredictable to cut, some stuff will cut ok with standard HSS holesaws ( the type with teeth ) others will strip the teeth off in a few seconds.
Grit blades will cope with any type.

A couple of tips;
Spray water on the blade as you are cutting. This will stop heat build up "blueing" the steel around the cut.

Re grind the pilot drill with a VERY shallow point - almost flat. That way it is less likely to spiral into the sheet when it breaks through.

Hope this is some help.

[Doggus]

Originally posted by one_rod
Re grind the pilot drill with a VERY shallow point - almost flat. That way it is less likely to spiral into the sheet when it breaks through.

Thanks for the tips everyone. One_rod, not sure what you meant by this...sorry, I'm with stupid.

Everybody is on the right track here - definitely use an abrasive hole saw.

I just had new engineered quartz countertops with an undermount stainless sink installed in my kitchen. All three holes for faucet/sprayer combo, soap dispenser and Instant Hot water were drilled through the countertop and sink flange together after installation. Engineered quartz is 93% quartz and 7% resin, 1 1/4" thick and 70% the hardness of a diamond, so it required a 1 1/4" diamond abrasive hole saw, some water as a lubricant, and patience. I have to admit, I didn't do it myself, just watched my contractor drill it. I did all the plumbing and hookup afterward.

The hole may be slightly oversized as Cutter pointed out , but the flanges on the faucets, soap dispenser, etc. will cover that. The soap dispenser plastic bottle neck was a bit small to stay centered in the hole, however a few wraps of adhesive aluminum tape around it resulted in a snug fit.

[one_rod]

Originally posted by Doggus
Thanks for the tips everyone. One_rod, not sure what you meant by this...sorry, I'm with stupid.

Sorry Doggus,

It's never easy to decide how "deep" to go with advice when you don't really know the person you are giving it to.

If you are not into grinding your own drillbits then ignore that part and stick to Cutters good advice about clamping wood to the back.

[Jerry]

You can use any bi-metal hole saw to cut through stainless steel. The thickness you are cutting through will be very easy. Use a little oil with the cutter. I have cut many holes through stainless steel from 20g. up to 1/8" thick. You will need a 1/4" pilot hole first.

[echo8287]

We use diamond hole saws to drill through SS sinks(and tile,and granite countertops) sometimes. I had a couple of used SS commercial sinks that I put in my garage and the holes weren't quite big enough and I used my plasma cutter to enlarge them. I wouldn't do this on my kitchen sink though. It worked pretty well,turned em a little blue around the hole.David